The operating costs of low-temperature evaporators revolve around equipment stability and treatment efficacy, encompassing five core aspects. While the proportion of each cost may vary slightly across different applications, the overall structure remains relatively fixed.

Firstly, energy consumption constitutes the core operational expense. Low-temperature evaporators rely on heat pump systems for operation, primarily consuming electrical power (for running core components such as compressors, circulation pumps, and vacuum pumps). Depending on treatment capacity, the average daily electricity consumption per unit typically ranges from 50 to 300 kWh, specifically influenced by wastewater concentration and evaporation volume. — When treating high-salinity, high-concentration wastewater, the higher viscosity of the material and slightly reduced heat transfer efficiency result in electricity consumption 15%-20% higher than when treating low-concentration wastewater. Compared to traditional steam-heated evaporation, while steam costs are eliminated, electricity consumption remains a significant expenditure.

Secondly, consumables and chemical costs arise. To prevent equipment scaling and ensure water quality, specialised chemicals must be added periodically: Firstly, scale inhibitors (such as polycarboxylic acids), added at 0.1-0.3kg per tonne of treated wastewater, costing approximately 20-50 yuan per kilogram; Secondly, cleaning agents (e.g., citric acid or hydrochloric acid solutions) are required for equipment maintenance every 1-2 months of operation, with a single cleaning cycle costing approximately ¥200-500. Additionally, certain equipment requires periodic replacement of consumable parts, such as vacuum pump oil (replaced every 3-6 months at a cost of 100-300 yuan per replacement) and seals (replaced every 6-12 months at a cost of 50-200 yuan per replacement). While these costs represent a relatively small proportion, they necessitate ongoing expenditure.

Equipment maintenance and overhaul costs also apply. Beyond routine basic upkeep, units require 1-2 comprehensive annual inspections, including checking heat pump compressor conditions, cleaning evaporator heat exchange tubes, and calibrating online monitoring instruments. Each overhaul costs approximately ¥1,000-5,000, depending on equipment scale and fault severity. Should core components (such as compressors) fail, replacement costs escalate significantly (tens of thousands of yuan), though such occurrences are infrequent and risks can be mitigated through regular maintenance.

Finally, labour and auxiliary system costs arise. Equipment requires dedicated operators and daily inspections. Assuming one operator per shift (monthly salary: ¥4,000–6,000), monthly labour costs amount to approximately ¥4,000–6,000. Additionally, auxiliary systems (e.g., circulating water systems, wastewater pre-treatment systems) incur minor operational costs, such as circulating water replenishment fees and pre-treatment chemical expenses, amounting to approximately 500-1000 yuan monthly. These represent a relatively minor proportion of overall expenditure.